GAO found that: (1) six major subordinate commands had negative ULO balances totalling about $328 million; (2) commands did not always resolve negative balances promptly; (3) coordination problems between the commands and other Department of Defense (DOD) organizations caused delays in resolving negative balances; (4) actions to correct negative ULO were slow because information on obligations, payments, or collection transactions was inaccurate or incomplete; and (5) contractor overpayments were the cause of $7.6 million in negative ULO and tied up Army funds that could have been used to meet other Army requirements. GAO also found that commands did not: (1) produce reports that showed how long their negative ULO balances had been outstanding; and (2) initiate adequate follow-up procedures to ensure that outstanding negative balances were resolved.